There are currently two international open document formats: Microsoft’s OOXML, and the truly open Open Document Format (ODF).
Microsoft bought and paid for its ISO certification last year. (OOXML is not open; Microsoft merely promises not to sue anyone for using its format.) As an extra layer of protection, perhaps, Microsoft’s published OOXML specification is a mess, and Microsoft Office does not conform to its own spec.
Even though Microsoft managed to coerce enough countries into voting to certify OOXML as an international open standard, many countries have made the use of ODF mandatory. As a result, Microsoft Office could become useless for anyone dealing with government documents.
For this reason, Microsoft will finally support ODF natively in the second service pack release, coming April 28th. There are rumors that future versions will even use ODF as the default file format (or be configurable to do so). Score one for open source!
Now when will U.S. courts finally embrace openness instead of relying on Microsoft’s proprietary standards?